High-speed printer

ABSTRACT

A high-speed printer comprising at least one type-bearing element on which there is arranged at least one series of characters, means adapted to move the type-bearing element continuously in a substantially horizontal plane so as to cause each character to travel along a closed path, a hammer adapted to effect the printing of the characters of the element on the fly and means for shifting the type-bearing element and the hammer with respect to a paper support for a distance corresponding to a character space while the first said means moves the series of characters past the hammer, which prints a character on the passage of each of the series of characters when there are more than one series.

United States Patent Perucca 51 July 11, 1972 s41 HIGH-SPEED PRINTER3,310,147 3/1967 Clary et a1 ..|0|/| 10 x 2,980,227 4/1961 Handley..197/20 [721 My 3,205,305 9/1965 Clark et al. .101/1 10 x [73]Assignee: lag. C. Ollvetfl SC., S.p.A., lvrea, 3,415,184 12/1968 Perucca..101/93 (Turin), Italy Primary xamimr-Robert E. Pulfrey [22] Elm: April1970 Assistant Examiner-R. T. Rader [2n AWL Na: 31,331 Attorney-Birch,Swindler, McKie & Beckett [57] ABSTRACT [30] Foreign Amman M Ahigh-speed printer comprising at least one type-bearing ele- April 23,1969 Italy "5154? A169 ment on which there is arranged at least oneseries of characters, means adapted to move the type-bearing elementcon- [52] U.S.Cl. ..l97/l8, 197/49, lot/93C in lly in a s n i lly hrizontal plane so as to cause [58] fleldolSearch..10l/110,93;197/18,48,49

[56] References Cited UNITED STATES PATENTS 2,476,841 7/1949 Colombo197/ l 8 2,31 1,737 2/1943 Colombo ..197/18 3,559,791 2/1971 WaldenBurger ..l0l/l 10 x each character to travel along a closed path, ahammer adapted to effect the printing of the characters of the elementon the fly and means for shitting the type-bearing element and thehammer with respect to a paper support for a distance corresponding to acharacter space while the first said means moves the series ofcharacters past the hammer, which prints a character on the of each ofthe series of characters when there are more than one series.

13Chlms, ISDraWingFIgures PITENTEDJHL 1 1 I972 SHEET 2 OF 8 INVENTOR. VINC ENZO PERUCCA ATTORNEYS PHENTEUJUL 11 m2 3.675.753

SHEET u nr 8 (I'IEVENTOR. vm N20 PERUCCA BY you (Lg 76am ATTORNEYSBACKGROUND OF THE INVENTION The technical problem which the presentinvention proposes to solve is the creation of a printer having greatersimplicity and greater flexibility of use than the printers describedabove. In the basic use of these high-speed printers, that is asperipheral units of data processing systems, it is frequently necessaryto change from the printing of alphanumeric data to the printing ofexclusively numeric data, that is the printing of a smaller number ofcharacters. The present invention proposes to create a printer adaptedto print from a complete series of characters (e.g., alphanumeric data)or only from a group of the characters, e.g., numeric data, the twotypes of data being printed a different speeds so as to give theprinting speed its optimum value in both cases.

SUMMARY OF THE INVENTION According to the invention, in a printer as setforth in the first paragraph above, at least one group of characters ineach series appears on the type-bearing element a plurality of times,and means for varying the speed are provided, being adapted to vary theratio between the speed of the shifting means and the speed of movementof the type-bearing element, a first ratio being used for the printingof the series of characters, a second ratio being used for the printingof the characters of the group of characters, and the ratio varying inproportion to the number of times that the said group and the saidseries of characters appear on the type-bearing element.

In a first printer of this type, the characters or types are arranged ona wheel with a vertical axis having a portion devoid of types in orderto allow recocking of the hammer. The speed of rotation of the typewheel is such that it performs a revolution while said wheel and saidhammer are shifted iDr a printing step, the printing taking place at therate of one character at each revolution of said wheel. The distributionof the characters has been given its optimum form by imposing the twoconditions that the hammer should completely cover each character in theactual printing position and that the hammer should not interfere withthe two adjacent characters when printing any given character.

In a second printer of the same type, the characters are arranged with aconstant spacing on an endless band movable at constant speed on twoconveying and guide drums slidable transversely together with a printinghammer. Printing takes place substantially in accordance with the sameprinciples as in the printer just described.

DESCRIPTION OF THE DRAWINGS FIG. I is a reduced-scale plan view of theprinter embodying the invention;

FIG. 2 is a more detailed plan view of a number of details of FIG. 1;

FIG. 3 is a front view, partly in section, of the printer of FIG.

FIG. 4 is a section on the line IV IV ofFIG. 1; FIG. 5 is amore detailedplan view of another detail of FIG.

FIG. 6 is a front view, partly in section, of the detail of FIG.

FIG. 7 is a section on the line VII VII of FIG. 6; FIG. 8 is a sectionon the line VIII VIII of FIG. 6; FIG. 9 is a more detailed plan view ofa third detail of FIG.

FIG. 10 is a from view, partly in section, of the detail of FIG.

FIG. 11 is a front view ofa detail of FIG. 4; FIG. I2 is a more detailedplan view of a type wheel; FIG. 13 is a diagram illustrating thedistribution of the characters and of the relevant synchronism signals.

2 DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment hereinafterdescribed, the printer according to the invention is designed forprinting on pages or leaves, for example on continuous forms.

The printer includes a carriage 31 (FIG. 1) which is guided during itstransverse movement by two series of rollers 32 (FIG. 4) supported bythe carriage itself and rotatable on two rails 33 arranged on the frameof the printer.

The carriage includes a first housing 36 (FIGS. 2 and 3) in which thereis mounted a series of eight type wheels 38. Each of these wheels 38 isfixed on a slightly inclined shaft 39. The wheels 38 are partlysuperimposed one over the other and are arranged at the minimum possibledistance from each other. Each shaft 39 is rotatable in two bearings 4|carried by the housing 36 and is connected through a pair of helicalgears 44 (FIG. 4) to a horizontal shaft 46 rotatable in turn in twobearings 47 (only one of which can be seen in the drawings) carried bythe housing 36. The shaft 46 tenninates in a slotted portion 48 (FIG. 3)engaged in a sleeve 49, which is rotatable in two bearings 51 fixed inthe frame of the printer. 0n the sleeve 49 there is fixed a pulley 53(FIG. I) connected by means of a toothed belt 54 to a pulley 56. Thepulley 56 is fixed on a shaft 57 of a conventional electric mOtor 58,which is started in a manner known per se when the machine is switchedon.

The carriage 31 includes a second housing 61 (FIGS. I and 2) in whichthere is mounted, in correspondence with each type wheel 38, a hammer 62adapted to effect printing on the fly. Each hammer 62 can pivot on a pin63 fixed to the housing 6] and is provided with a projection 66 curvedin accordance with the radius of the wheels 38 and having a transversedimension such as to be able to cover each character completely in itsprinting position, as will be better explained hereinafter. Each hammer62 is normally caused to bear by the action of a spring 68 against anextension 69 of a spring damper 71. Finally, each hammer 62 is providedwith an arm 72 to which there is fixed a pack of laminations forming anarmature 73 for a striking electromagnet 74 fixed to the housing 61.Each electromagnet 74 is connected through a pair of Wires 76 (FIG. I)to an electronic control unit of the printer, the control unit not beingshown in the drawings. The electromagnets 74 are normally deenergizedand are energized selectively for striking.

Each type wheel 38 is divided into two portions indicated by thereferences A and B, respectively, in FIGS. 12 and 13. In portion A thereis arranged a first series of alphanumeric characters 81 and in portionB there is arranged a series of humeric characters 82 together with anumber of operative and algebraic symbols. The numeric characters andthe operative and algebraic symbols forming part of the series ofalphanumeric characters 81 are disposed on the wheels 38 in a portion Cin a position diametrically opposite the corresponding characters andsymbols 82.

As will be better described hereinafter, the printer is adapted whenoperating to function Mr the printing of alphanumeric characters or ofthe numeric characters only. Moreover, the printing is effected bothwith the carriage moving from Iefl to right and with the carriage movingfrom right to lefi.

Furthermore, in the present embodiment, the printer has been arranged sothat in the printing of the central character of the portion A, foralphanumeric printing, and in the printing of the central characters ofthe portions B and C, for numeric printing, the axis of the wheel 38,the axis of said central characters and the axis of the hammer 62 are inalignment. If it is desired that the characters be printed with constantspacing, the characters other than the central ones will be printed whentheir axis is not on the line joining the axis of the wheel 38 and theaxis of the hammer 62. The hammer 62 must therefore be of a width suchas to cover each character in its printing position.

The synchronism signals for the printing of the characters 81 and 82 aresupplied by four series of holes 86, 87, 88 and 89 formed in a disc 90fixed on the sleeve 49 and therefore movable in synchronism with thewheels 38. The arrangement of these holes 86, 87, 88 and 89 in relationto the corresponding characters 38 is shown in the diagram of FIG. 12.The synchronism signals are generated by the holes 86, 87, 88 and 89 inco-operation with four phototransistors 91, 92, 93 and 94 and a lamp 96(FIG. 3). The phototransistors 91, 92, 93 and 94 are connected to thecontrol unit of the printer by means of the pairs of wires 97. The holes86, 87, 88 and 89 refer respectively to the cases of alphanumeric ornumeric printing with the carriage 31 moving from lefi to right or fromright to left.

In the disc 90 there is moreover formed a hole 98 (FIG. 13) arranged insuch manner as to pass in front of a phototransistor 99 when the linebisecting the portion B of the wheels 38 comes into correspondence withthe printing zone. The phototransistor 99 is also connected to thecentral control unit by means of a pair of wires 101. Finally, in thedisc 90 there are formed two holes 104 disposed on the same circum'ference and otf-set through 90' with respect to the hole 98, so thatthey are positioned in correspondence with the center lines between theportions B and C. The holes 104 co-operate with a phototransistor 106connected to the central control unit of the printer by means of twowires 107.

The characters 81 and 82 are arranged on the wheels 38 in such mannerthat the greatest posible number thereof can be accommodated. Inessence, the characters are distributed on the wheels 38 by imposing thefollowing conditions: the hammer 62 must be of a width such as to covereach of the characters 81 and 82 completely in its printing position;the characters 81 and 82 must be arranged at a distance from each othersuch that the hammer does not interfere with the adjacent charactersduring its striking action; the portion B and the portions between B andC must be of an amplitude such as to allow the recocking of the hammer.This calculation can be solved analytically or by means of an electronicprocessor and supply the law of distribution of the characters 81 and82, the law of distribution of the holes 86, 87, 88 and 89 and the widthof the hammer 62 as a function of the diameter of the wheels 38, theprinting step and the width of the characters. More precisely, theselaws will be found by the combination of the laws relating to the fourcases of alphanumeric and numeric printing with the carriage 31 movingfrom left to right or from right to left.

Through the space between the housings 36 and 61, and therefore betweenthe wheels 38 and the hammers 62, passes the paper in the form ofcontinuous forms 111 (FIGS. 1 and 4) fed through the medium of two drawpin wheels 112 known per se. The forms 111 are moreover guided through afunnel 113, in which a paper holder 114 is arranged, and over a shapedplate 116 which guides the paper as far as the pin wheels 112.

The carriage 31 is provided with an am 121 which is provided in turnwith a stud 122 engaged in a fork 123 of a slider 124 (FIGS. and 6). Theslider 124 is guided in the grooves 126 of four rollers 127 rotatable ona housing 128 fixed to the frame of the printer. Two rollers 131 canrotate on the slider 124 and co-operate with a earn 132 fixed on a shaft133 which is rotatable in two bearings 134 fixed to the housing 128. Thecam 132 therefore has the characteristic of being of constant diameteron the pitch line.

The shaft 133 is coupled by means of a pair of helical gears 136 to ashaft 138 rotatable in two bearings 139 fixed in the housing 128. Theshaft 138 is provided with a gear 141 meshing with a gear 142 fixed on ashaft 143 rotatable in two bearings I44 fixed in the housing 128. On theshaft 143 there is fixed a second gear 146 meshing with a gear 147 on asleeve 148. The transmission ratio between the sleeve 148 and the shaft138, which derives from the product of the transmission ratios betweenthe gears 148 and 146 and the gears 142 and 141, is 1 2. The sleeve 148is rotatable by means of a bearing 149 on a shaft 151, which isrotatable in turn in a bearing I53 fixedin the housing 128 and in abearing 154 fixed in a recess in the shaft 138. On the shaft 151 thereis fixed a pulley 156 connected by means of a belt 157 (FIG. 1) to apulley 158 integral with the pulley $3 and therefore fixed on the sleeve49. The transmission ratio between the pulley I56 and the pulley 158 isl :4.

The shaft 151 ha two central slotted portions 160 in which there areslidable two collars 161 and 162 urged in opposite directions by aspring 163. The collar 161 is provided with a toothed rim 166 adapted toengage with a toothed rim 166 adapted to engage with a toothed rim 167of the shaft 138. The collar 162, in turn, is provided with a toothedrim 168 adapted to engage with a toothed rim 169 of the sleeve 148. Thecouplings formed between the toothed rims 166 and 167 (FIG. 7) andbetween the toothed rims 168 and 169 (FIG. 8) are off-set in relation toone another by an angle of 22"30'.

The two collars 161 and 162 are provided with grooves or races 171 and172, respectively, (FIGS. 5 and 6), in which there engage two rollers173 and 174 rotatable on two levers 176 and 177 fulcrumed on the housing128. The lever 176 has a projection 178 adapted to co-operate with aprojection 179 of the lever 177. Moreover, the two levers 176 and 177are provided with two projections 181 and 182, respectively,constituting the armatures of two electromagnets 183 and 184 fixed tothe housing 128. The two electromagnets 183 and 184 are respectivelyconnected by means of a pair of wires 186 and 187 to the central controlunit and are normally kept energized.

At the end of the shaft 133 there is fixed a disc 188 provided along afirst circumference with a pair of slots 189 which, in cooperation witha lamp 191 and a phototransistor 192 and by means of a pair of wires193, are adapted to send to the central control unit an indication thatthe carriage 31, and therefore the wheels 38, are in the printingposition. The disc 188 is provided along a second circumference withanother pair of slots 194 which, in co-operation with the lamp 191 and aphototransistor 195 and by means of a pair of wires 196, are adapted tosend to the central control unit an indication that the carriage 31 isin the two rest or inoperative positions on the left or right. Finally,the disc 188 is provided with another slot 197 which, in cooperationwith the lamp 191 and a phototransistor 198 and by means of a pair ofwires 199, is adapted to send to the central control unit an indicationthat the carriage 31 is in the rest or inoperative position on the wetrerne left of its travel.

Between the paper 111 and the type wheels 38 there moreover an inkedribbon 201 (FIGS. 1 and 4) which unwinds alternately from a pair ofspools 202 and 203 and is guided over four rollers 204 disposed at thevertices of a rectangular frame 206. The frame 206 includes a lowersupport 207 provided with two lugs 208 each of which can pivot on a pin209 fixed to the frame of the printer.

The support 207 is moreover provided with a lug 211 on which there ismounted a roller 212 normally bearing against a linear cam 213 (FIG. 11)formed on the frame of the printer. Each lug 208 (FIGS. 1 and 4) isprovided with an extension 214 to which there is fixed a stud 216adapted to co-operate with a spring-biased positioning member 217. Thespringbiased positioning members 217 allow the frame 206 to be free inits normal working position and are able to hold it in two differentpositions: the first, indicated in FIG. 4 in broken lines, is theposition that the frame must adopt to enable the ribbon to be changed,the second, indicated in chain-dotted lines in the same drawing, is theposition that the frame is made to adopt for carrying out servicing ofthe wheels 38.

Finally, the frame 206 includes an upper plate 218 provided with twolateral lugs 219 which can be used to facilitate the raising of theframe itself.

The ribbon 201 is wound on each of the spools 202, 203 by passingthrough two corresponding pairs of pins 221 and 222 fixed to a slider204 (FIG. 9). The slider 224 is guided on two fixed pins 226 on each ofwhich a roller 228 can moreover rotate, the roller being also used as aguide for the ribbon 201. At the two ends of the ribbon 201 there isfixed a stop 231 having dimensions such that it cannot pass through thepairs of pins 22 1 and 222.

Each spool 202, 203 (FIG. consists of a base plate 233, aribbon-carrying core 234 rendered fast with the plate 233 for rotationby means of a stud 236 on the plate 233 which is inserted in a recess237 in the core itself, and an upper cover plate 238.

The two base plates 233 are connected to two corresponding shafts 241,242 by a spring 243 wound on the corresponding shaft and connected byone end to the shaft itself and by the other to the plate 233. Eachplate 233 is moreover provided with a dog 246 (FIG. 9) adapted to engagewith a dog 247 on the corresponding shaft 241, 242.

Each of the shafts 241 and 242 is rotatable in two bearings 249 (FIG.10) fixed in the frame of the printer and is provided with a frictionbrake 251 known per se. The shafts 241 and 242 are moreover connectedthrough two pairs of helical gears 253 and 254, respectively, to twosleeves 256 and 257 rotatable on a shaft 258, which is rotatable in turnin the frame of the printer through the medium of two bearings 259. Theshaft 258 is connected to the shaft 138 by means of a flexible coupling261 (FIG. 1) known per se.

The sleeves 256 and 257 (FIG. 10) are provided with toothed rims orrings 263 and 264, respectively, which are adapted to co-operate withtwo toothed rims 266 and 267 formed at the ends of a sleeve 268 slidableon the shaft 258, but fast angularly therewith. The sleeve 268 has agroove 271 in which there engages a roller 272 carried by a crank 273(FIG. 9) fixed to a shafi 274 rotatable in the frame of the printer.

On the shaft 274 there is fixed a second crank 276 provided in turn witha roller 277 adapted to co-operate selectively with two inclinedprofiles 278 and 279 of a lever 281 fulcrumed on the slider 224 andnormally held in contact with the roller 277 by a spring 282.

The printer operates in the following manner. The switching-on of themachine causes the closing of the circuit of the motor 58 (FIG. 1),which begins to rotate and, through the pulley 56, the belt 54 and thepulley 53, sets the sleeve 49 (FIGS. 2 and 3) in rotation. The sleeve,in turn, causes the shaft 46 to rotate and, through the gears 44, saidshaft sets the shafts 39 and, therefore, the eight type wheels 38 inanticlockwise rotation. Moreover, through the pulley 158, the belt 157and the pulley 156 (FIG. 1), the shaft 151 (FIGS. 5 and 6) is set inrotation.

The electromagnets 183 and 184 are both energized and hold thecorresponding levers 176 and 177 so that they are turned anticlockwiseand clockwise, respectively. The two collars 161 and 162 are thuspressed one against the other in opposition to the action of the spring163.

The switching-on of the machine moreover produces the lighting of thelamps 96 (FIG. 3) and 191 (FIG. 6). Assuming that the printer is in thestate shown in the drawings, the disc 188 (FIG. 5) is disposed with theslots 194 and 197 in correspondence with the lamp 191 and thephototransistors 195 and 198.

When the store containing the data signals that it is available forprinting a line of characters, the central control unit carries out ascanning of these characters to detennine whether the characters to beprinted are alphanumeric or only numeric. Let it be assumed that a lineof alphanumeric characters is to be printed.

On the basis of this indication and on the basis of the indication bythe phototransistor 198 that the carriage 31 is stationary at theleft-hand end of the line, the input into the control unit of thesignals coming from the photoelectric cells 91 and 99 appertaining tothe holes 86 and 98 in the disc 90 (FIGS. 3 and 13) is activated.Moreover, the electromagnet 183 (FIGS. 5 and 6) is deenergized. Thespring 163 therefore shifts the collar 161 to the right. The lever 176turns clockwise. bringing the projection 178 into the path of theprojection 179 of the lever 177. Any possible erroneous deenergizstionof the electromagnet 184 therefore has no effect, since the lever 177cannot turn anticlockwise.

The collar 161, on shifting to the right, produces the meshing of thetoothed rim 166 with the toothed rim 167 of the shaft 138 which, throughthe gears 136, causes the shaft 133 to rotate clockwise. The cam 132,acting through the rollers 131, shifts the slider 124 to the right and,therefore, the carriage 31 with a considerable initial acceleration andthen with a uniform motion.

Afier a rotation of about 15, one of the slots 189 (FIG. 5) isinterposed between the lamp 191 and the phototransistor 192, which sendsto the control unit the information that the machine is ready to receivethe first group of characters. On the first passage ofthe hole 98 in thedisc (FIGS. 3 and 13) in correspondence with the phototransistor 99,this element enables the control circuits of the eight hammers 62 toinitiate the count of the signals sent by the phototransistor 91 on thepassage of each hole 86. The electromagnets 74 (FIGS. 2 and 3) areenergized selectively for the printing of the signals contained in thestore by means of the pulses which cause the attraction of the armature73, and therefore the anticlockwise turning movement of the hammer 62,which strikes by means of the projection 66 against the paper 111, thuspressing it, together with the inked ribbon 201, against thecorresponding type of the wheel 38.

The rotation of the shaft 133 takes place at a speed such as to shiflthe carriage 31 by one character space for each rotation of a revolutionof the wheels 38 and, therefore, also of the disc 90. At each passage ofthe hole 98 in correspondence with the phototransistor 99, the count ofthe signals sent by the phototransistor 91 resumes from zero and theselection of another eight characters to be printed therefore takesplace. Eight line portions are thus printed at the same time, eachportion being able to contain a predetermined number n of characters.

Afier the hole 98 has started the n-th printing cycle, the slot 189comes to an end. The phototransistor 192 is deenergized and, in responseto this signal, the central control unit of the machine interrupts thetransmission of the signals.

On the following first passage of the hole 98 in correspondence with thephototransistor 99, a request is made to the control unit for orders forthe printing of the following line.

The control unit may command the arrest of the carriage 31. In thiscase, the electromagnet 183 (FIG. 5) is reenergized and the collar 16]is brought back to the left, disengaging the rim 166 from the rim 167.The carriage is thus stopped at the right-hand end of the line.

The arrest of the carriage may depend on the fact that the data to beprinted are finished. In this case, no other instruction is associatedwith this instruction for arrest of the carnage.

On the other hand, the instruction for arrest of the carriage may beassociated with the instruction for causing the forms 111 to perform ajump for a number of line spaces greater than that which can be effectedin the time of mere reversal of the movement of the carriage 31. TheIine spacing and jumps are effected through a rotation of the pin wheels112.

Finally, the order for arrest of the carriage 31 may be associated withan indication that the following line is composed of numeric charactersonly. What happens in this case will be described hereinafter.

The position of the carriage 31 stationary at the right-hand end of theline is signalled by the photoelectric cell 198.

The control unit may, on the other hand, command the carriage 31 tocontinue on its course. This command is always associated with thecommand for making at least one space between the lines. Thereafter, thefirst signal sent to the control unit by the phototransistor 99 causesthe deactivation of the phototransistor 91 and the activation of thephototransistor 92 (FIGS. 3 and 13) corresponding to the holes 87 in thedisc 90. The holes 87 control precisely the synchronism in the printingof the alphanumeric characters when the carriage 31 moves from right toleft. The cam I32 reverses the direction of movement of the slider 124and, therefore, of the carriage 31, which beings to move from right toleft. When the slot 189 brings the phototransistor 192 back into thelight again, the control unit enables the store to send the signals forthis second line. The printing of this second line takes placesubstantially in the manner described for the preceding line.

Let it now be assumed that a line of only numeric characters is to beprinted, with the carriage 31 positioned at the lefthand end of the lineitself. The control unit activates the inputs for the signals comingfrom the photoelectric cells 93 and 106 corresponding to the holes 88and 104 in the disc 90 (FIGS. 3 and 13). Moreover, the electromagnet 184(FIG. 5) is deenergized. The sprinG 163 shifts the collar 162 to theleft. The lever 177 turns anticlockwise, bringing the projection 179into the path of the projection 178 of the lever 176, which thus remainslocked in the inoperative position.

The collar 162, on shifting to the left, causes the meshing of thetoothed rim 168 with the toothed rim 169 of the sleeve 148 which,through the couplings formed between the gears 147 and 146 and betweenthe gears 142 and 141, causes the shaft 138 to rotate. Through thecoupling between the gears 136, said shaft causes clockwise rotation ofthe shaft 133 and, therefore, of the cam 132 at twice the speed withrespect to that used before for the alphanumeric printing. The cam 132shifts to the right the slider 124 and, therefore, the carriage 31,which is now shifted for a distance corresponding to the characterspace, while the type wheels 38 rotate for half a revolution.

The coupling between the toothed rims 168 and 169, as has already beensaid, is off-set through an angle of 2230 with respect to the couplingbetween the toothed rims 166 and 167 (FIGS. 7 and 8). The shaft 151therefore rotates through 2230 before beginning to transmit the motionto the shaft 138. This rotation corresponds to a 90 rotation of thesleeve 49 (FIG. 3) and, therefore, of the type wheels 38, the zero axisof which will no longer be the axis forming the line bisecting theportions 8 and C, but the axis perpendicular thereto. The centralcharacter, which was reached before after a l80 rotation of the wheel 38from the instant of the reading of the hole 98 in the disc 90 (FIGS. 3and 13), is now reached after a rotation of only 90 with respect to theholes 104. In fact, the speed of the carriage 31 is twice as great.There are therefore two central characters, which are the centralcharacters of the portions B and C, which are printed when their axis ison the line joining the axes of the hammer 62 and the wheel 38.

The transmission of the data to be printed is still controlled by theslots 189 (FIG. 5) and, therefore, by the phototransistor 192. Thecontrol circuits of the hammers 62 are reset by the passage of the holes104 in the disc 90 in correspondence with the phototransistor 106 andthen count the holes 88 by means of the phototransistor 93, whichproduces selective energization of the electromagnets 74 of the hammers62. At each revolution of the wheels 38, two characters are printed foreach wheel, one for the portion B and one for the portion C.

At the end of the printing of the line, the control unit provides, inthe manner already described, for sending the orders for the followingline. The arrest of the carriage now takes place by energizing theelectromagnet 184. In the event of the printing having to be continued,the order for effecting linespacing for the forms 111 is sent, thephototransistor 93 is deactivated and, instead, the phototransistor 94is activated, which corresponds to the holes 89 in the disc 90 whichcontrol the synchronism for the printing of the numeric characters whenthe carriage 31 shifts from right to left.

The deenergization of one of the electromagnets 183 and I84 (FIGS. 5 and6), as described, sets in rotation the shaft 138 (FIGS. 5 and 6) and,therefore, through the coupling 261 (FIGS. I and the shaft 258. Theshaft 258 causes the sleeve 268 to rotate and, therefore, assuming theposition to be as shown in the drawings, causes the sleeve 257 to rotatethrough the coupling between the toothed rims 267 and 264. The sleeve257, in turn, causes the shaft 242 (FIGS. 9 and 10) to rotate throughthe coupling between the gears 254. The shaft 242 rotates and compressesthe spring 243 until its dog 247 encounters the dog 246 of the spool203, which thus also begins to rotate clockwise. The ribbon 201 is woundaround the core 234, being guided on the rollers 226, the pins 222, thefour rollers 204 and the pins 221 and unwinding from the spool 202.

The spool 202 also rotates for a certain distance, loading the spring243 until its dog 246 encounters the dog 247 of the shaft 241. Theribbon 201 is subjected to a certain pull due to the action of the brake251, which opposes the rotation of the shaft 241. The ribbon 201 thushas a first movement of translation with respect to the paper 111.

During the movements of the carriage 31 from left to right and viceversa, it displaces the cam 213 with respect to the roller 212. Theframe 206 (FIG. 4) is turned anticlockwise initially and raises theribbon 201 with respect to the wheels 38. The point of maximum height isreached when the carriage 31 is at the halfway point of its travel. Theribbon 201 must therefore have a height, or width, sufficient for it toremain always in correspondence with the wheels 38. As alreadydescribed, the carriage 31 can stop only at the two ends on the rightand left; in these two positiom, the ribbon 201 is lowered, so that thelast printed line can also be read.

In the event of the carriage 31 stopping, the shaft 258 also stops and,therefore, the driving spool 203 stops. Due to iner tia, the spool 202tends to continue its rotation, thus causing a slackening of the ribbon201, which could bear against the wheels 38 still in motion andtherefore break. The springs 243 stretch, however, to return to theirnormal inoperative position, causing the two spools 202 and 203 torotate in the opposite direction to the previous one and bringing theribbon 201 under tension again.

When the portion of ribbon 201 wound on the spool 202 is about to cometo an end, the stop 231 engages with the pins 221 and shifts the slider224 to the right until the roller 277 of the crank 276 passes from theprofile 278 to the profile 279 of the lever 281. Owing to the action ofthe spring 282, the roller 277 slides on the profile 279, causing thecrank 276 to turn anticlockwise very rapidly together with the shaft 274and the crank 273. This crank shifts the sleeve 268 to the right throughthe roller 272, disengaging the rim 267 from the rim 264 and engagingthe rim 266 with the rim 263.

The sleeve 256 thus begins to rotate and, through the coupling betweenthe wheels 253, sets the shaft 241 in rotation anticlockwise. The shaftrotates and loads the corresponding spring 243 until its dog 246encounters the dog 247 of the spool 202, which thus becomes the drivingspool for the ribbon 201, which is wound thereon and unwinds from thespool 203. When the ribbon wound on the spool 203 reaches its end, theoperation which has just been described is repeated in a substantiallyidentical manner.

Replacement of the ribbon is effected by raising the frame 206 manuallyby means of the lugs 209 as far as the position indicated in brokenlines in FIG. 4.

Servicing and cleaning of the wheels 38, on the other hand, is effectedby raising the frame 206 as far as the position indicated inchain-dotted lines in FIG. 4. In this position, the wheels 38 are infact completely free or exposed.

It is understood that various modifications may be made in the printerdescribed without departing from the scope of the invention. Forexample, the portions for recocking the hammer may be eliminated bydeciding to print one character every two revolutions of the type wheel.The printing is effected during the first revolution of the type wheel,while the second revolution is used for recocking the hammer. In thisway, the characters may be distributed over the entire circumference ofthe wheel.

If the characters to be printed are few in number, they may also appearmore than twice on the type wheel, being spaced apart each time by aportion devoid of characters and having an amplitude sufficient toensure the recocking of the hammer. ln this case, at each revolution ofthe wheel, there is printed a number of characters equal to the numberof times that the characters appear on the wheel. The carriage, on theother hand, performs a travel of one character space while the typewheel performs a rotation corresponding to the sum of a portion devoidof characters and a portion bearing one of these series of characters.

Finally, both in the printer described and in the examples which havejust been indicated, the type wheels may be replaced by an endless bandwhich can revolve on two spools carried by a carriage.

lt is to be understood that the invention is not to be limited to thespecific form or arrangement of parts herein described and shown, but islimited only by the scope of the appended claims.

l'claim:

1. A high-speed printer comprising at least one type-bearing element onwhich is arranged a plurality of characters organized into at least onefirst series of characters and at least two identical second series ofcharacters, said second series of characters appearing on saidtype-bearing element a plurality of times for each appearance of saidfirst series of characters,

means to move said type-bearing element continuously in a substantiallyhorizontal plane so as to cause each of said characters to travel aclosed path,

a hammer to effect the printing of said characters on the fly,

a paper support for holding paper upon which said charac ters will beprinted interposed between said hammer and said type-bearing element,

means for shifting said type-bearing element and said hammer withrespect to said paper support throughout a printing zone a distancecorresponding to a character space during the interval in whichsuccessive selected characters on said type-bearing element arepositioned in front of said hammer,

means for varying the ratio of the rate of movement of said shiftingmeans to the rate of movement of said type-bearing element and saidhammer between a first ratio used when printing said characters of saidfirst series of characters and a second ratio used when printing saidcharacters of said second series of characters.

2. A printer according to claim 1 wherein said first ratio and saidsecond ratio are dependent upon the number of times said first series ofcharacters and said second series of characters appear on saidtype-bearing element.

3. A printer according to claim 2 wherein said type-bearing element andsaid hammer are mounted in spaced relationship upon a carriage, andwherein said means for varying the ratio of the rate of movement of saidshifting means to the rate of movement of said type-bearing element andsaid hammer acts on said carriage, operating said carriage at a firstrate for printing said first series of characters and at a second ratefor printing said second series of characters.

4. A printer according to claim 1 wherein for each appearance of saidfirst series of characters on said type-bearing element, said secondseries of characters makes a first appearance centrally disposed in eachof said series of characters and a second appearance diametricallyopposite thereto, and wherein said type-bearing element includesportions devoid of said characters to provide intervals for recockingsaid hammer.

5. A printer according to claim 4 wherein said type-bearing element andsaid hammer are mounted in spaced relationship upon a carriage andwherein said means for varying the ratio of the rate of movement of saidshifting means to the rate of movement of said type-bearing element andsaid hammer acts on said carriage, said carriage moving at a first ratefor printing said first series of characters and a second rate forprinting said second series of characters.

6. A printer according to claim 5 wherein said means for shifting saidtype-bearing element and said hammer comprises a first electromagneticclutch selectively connecting said carriage to a means for driving saidcarriage at said first rate, and

a second electromagnetic clutch selectively connecting said carriage toa means for driving said carriage at said second rate, and

means for selectively engaging said first clutch or said second clutch.

7. A printer according to claim 6 wherein said means for shifting saidtype-bearinG element and said hammer further comprises a rotatable camdriven by said selected clutch and having a camming surface engaging aconnecting link attached to said carriage, said cam causing saidcarriage to move with a uniform motion throughout said printing zone ata rate dependent upon said selected clutch driving said cam.

8. A printer according to claim 7 wherein said cam is rotatable in twoopposite directions and said carriage is transversely movable in twodirections.

9. A printer according to claim 8 further comprising means forsynchronizing the printing action of said hammer with the arrival ofsaid selected one of said characters in front of said hammer.

10. A printer according to claim 9 wherein said type-bearing elementcomprises a type wheel rotatable on a substantially vertical shaft, andwherein said means for synchronizing comprises a disc having a pluralityof openings therein corresponding to said characters and rotatable insynchronism with said type wheel, and hammer control means activatingsaid hammer upon the passage of a predetermined number of openings,whereby the presence of said selected character is sensed in front ofsaid hammer.

11. A printer according to claim 10 wherein said openings are so phasedwith said characters to which said openings correspond that said hammerprints said characters on one line vertically adjacent with saidcharacters of another line.

12. A printer according to claim 10 further comprising a plurality oftype wheels and a plurality of hammers shifted together by said meansfor shifting, the axes of said type wheels being slightly inclined anddisposed apart a distance less than the diameter of said wheels wherebyadjacent wheels partially overlap, each of said wheels printing saidcharacters for a portion of said printing zone, said characters beinginclined on said wheels opposite and equal to the inclination of saidaxes whereby said characters are printed substantially vertically.

13. A printer according to claim 12 further comprising an inclinedribbon mounted in a frame and interposed between said hammers and saidpaper.

1. A high-speed printer comprising at least one type-bearing element onwhich is arranged a plurality of characters organized into at least onefirst series of characters and at least two identical second series ofcharacters, said second series of characters appearing on saidtype-bearing element a plurality of times for each appearance of saidfirst series of characters, means to move said type-bearing elementcontinuously in a substantially horizontal plane so as to cause each ofsaid characters to travel a closed path, a hammer to effect the printingof said characters on the fly, a paper support for holding paper uponwhich said characters will be printed interposed between said hammer andsaid typebearing element, means for shifting said type-bearing elementand said hammer with respect to said paper support throughout a printingzone a distance corresponding to a character space during the intervalin which successive selected characters on said type-bearing element arepositioned in front of said hammer, means for varying the ratio of therate of movement of said shifting means to the rate of movement of saidtype-bearing element and said hammer between a first ratio used whenprinting said characters of said first series of characters and a secondratio used when printing said characters of said second series ofcharacters.
 2. A printer according to claim 1 wherein said first ratioand said second ratio are dependent upon the number of times said firstseries of characters and said second series of characters appear on saidtype-bearing element.
 3. A printer according to claim 2 wherein saidtype-bearing element and said hammer are mounted in spaced relationshipupon a carriage, and wherein said means for varying the ratio of therate of movement of said shifting means to the rate of movement of saidtype-bearing element and said hammer acts on said carriage, operatingsaid carriage at a first rate for printing said first series ofcharacters and at a second rate for printing said second series ofcharacters.
 4. A printer according to claim 1 wherein for eachappearance of said first series of characters on said type-bearingelement, said second series of characters makes a first appearancecentrally disposed in each of said series of characters and a secondappearance diametrically opposite thereto, and wherein said type-bearingelement includes portions devoid of said characters to provide intervalsfor recocking said hammer.
 5. A printer according to claim 4 whereinsaid type-bearing element and said hammer are mounted in spacedrelationship upon a carriage and wherein said means for varying theratio of the rate of movement of said shifting means to the rate ofmovement of said type-bearing element and said hammer acts on saidcarriage, said carriage moving at a first rate for printing said firstseries of characters and a second rate for printing said second seriesof characters.
 6. A printer according to claim 5 wherein said means forshiftIng said type-bearing element and said hammer comprises a firstelectromagnetic clutch selectively connecting said carriage to a meansfor driving said carriage at said first rate, and a secondelectromagnetic clutch selectively connecting said carriage to a meansfor driving said carriage at said second rate, and means for selectivelyengaging said first clutch or said second clutch.
 7. A printer accordingto claim 6 wherein said means for shifting said type-bearing element andsaid hammer further comprises a rotatable cam driven by said selectedclutch and having a camming surface engaging a connecting link attachedto said carriage, said cam causing said carriage to move with a uniformmotion throughout said printing zone at a rate dependent upon saidselected clutch driving said cam.
 8. A printer according to claim 7wherein said cam is rotatable in two opposite directions and saidcarriage is transversely movable in two directions.
 9. A printeraccording to claim 8 further comprising means for synchronizing theprinting action of said hammer with the arrival of said selected one ofsaid characters in front of said hammer.
 10. A printer according toclaim 9 wherein said type-bearing element comprises a type wheelrotatable on a substantially vertical shaft, and wherein said means forsynchronizing comprises a disc having a plurality of openings thereincorresponding to said characters and rotatable in synchronism with saidtype wheel, and hammer control means activating said hammer upon thepassage of a predetermined nUmber of openings, whereby the presence ofsaid selected character is sensed in front of said hammer.
 11. A printeraccording to claim 10 wherein said openings are so phased with saidcharacters to which said openings correspond that said hammer printssaid characters on one line vertically adjacent with said characters ofanother line.
 12. A printer according to claim 10 further comprising aplurality of type wheels and a plurality of hammers shifted together bysaid means for shifting, the axes of said type wheels being slightlyinclined and disposed apart a distance less than the diameter of saidwheels whereby adjacent wheels partially overlap, each of said wheelsprinting said characters for a portion of said printing zone, saidcharacters being inclined on said wheels opposite and equal to theinclination of said axes whereby said characters are printedsubstantially vertically.
 13. A printer according to claim 12 furthercomprising an inclined ribbon mounted in a frame and interposed betweensaid hammers and said paper.